Print head and image forming device

A print head, comprising:

• a plurality of light emitting elements spaced along a main scanning direction at an element arrangement pitch;
• a plurality of drive circuits spaced along the main scanning direction at the element arrangement pitch, each light emitting element being connected to a respective one of the drive circuits, each driving circuit including a capacitor configured to control a light emission level of the light emitting element according to a charge level of the capacitor;
• a control circuit connected to the plurality of drive circuits and configured to control emission of light from the plurality of light emitting elements by supply of electrical signals to the plurality of drive circuits in groups, each group of drive circuits being drive circuits adjacent to one another in the main scanning direction;
• a plurality of first group wirings connecting the control circuit to one of the groups of drive circuits, wherein
• a difference in length between any first group wiring in the plurality of first group wirings and every other first group wiring in the plurality of first group wirings is less than the element arrangement pitch, and
• each first group wiring includes a first main wiring portion that is connected to the control circuit and extends in the main scanning direction and a first branch wiring portion that branches from the first main wiring portion at a first branch position, the first branch wiring portion being connected to the respective drive circuit and extending in a sub-scanning direction intersecting the main-scanning direction.

An image forming device, comprising:

• a print head configured to selectively emit light according to image data to be printed, the print head including:
• a first light emitting element on a substrate;
• a first drive circuit connected to the first light emitting element and including a first capacitor, the first drive circuit being configured to control a light emission level of the first light emitting element by charging the first capacitor to a target level;
• a second light emitting element on the substrate and separated from the first light emitting element by an element arrangement pitch value along a main scanning direction parallel to the substrate;
• a second drive circuit connected to the second light emitting element and including a second capacitor, the second drive circuit being configured to control a light emission level of the second light emitting element by charging the second capacitor to a target level;
• and
• a control circuit on the substrate and connected to the first drive circuit by a first wiring and the second drive circuit by a second wiring, the control circuit being configured to individually control voltages across the first and second capacitors at a predetermined timing, wherein
• a difference between a length of the first wiring and a length of the second wiring is less than the element arrangement pitch value,
• the first wiring includes a first main wiring portion that is connected to the control circuit and extends in the main scanning direction and a first branch wiring portion that branches from the first main wiring portion at a first branch position, the first branch wiring portion being connected to the first drive circuit and extending in a sub-scanning direction that is parallel to the substrate, but intersecting the main-scanning direction, and
• the second wiring includes a second main wiring portion that is connected to the control circuit and extends in the main scanning direction and a second branch wiring portion that branches from the second main wiring at a second branch point, the second branch wiring portion being connected to the second drive circuit and extending in the sub-scanning direction.